Population genetics

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What is it?

  • Field of gentics is connected with changes in genetic variation within a group of individuals over time. 
  • Population genetics want to know the extent of genetic variation within populations, and how it changes over many generations. 
  • Fielf of population genetics merge as a branch if genetis in 1930 and 1920.

Genes in populations and the hardy weinberg equation 

  • In the field of population genetics, focus shifts away from individual and onto the population of which the individual is a member. 
  • Population genetics may seem like a significant departure from other topics.. 
  • Extension of the Mendel's law of inhertience, molecular genetics and the idea of Darwin. 
  • Alleles of every gene in a population make up gene pool. 

Population is a group of interbreeding individuals that share a gene pool

  • Term population is a group of individuals of the same species that occupy the same region and can interbreed with one another. 
  • Species occupy a wide geographic eange and are divided into discete populations. 
  • Population of a given species may be located on diffrent continents, or population on the same continent may be divided by a geographical feature such as a large mountain range. 

Some genes may be monomorphic but some are plymorphic 

  • Term genetic polumorphism, refers to the onservation that many inhertited traits display variation within a population. 
  • Gentic polymorphisms referred to variation in inherited traits that are observable with the naked eye. 
  • Polymorphisms in color and patten have long attracted the attention of population geneticists. 

The Hardy-Weinberg Equation can be used to calculate Genotype Frequencies based on allele frquencies 

  • 1908, Hardy and Weinberg derived a simple mathematical expression that predicts stability of allele and genotype frequencies from one generation to the next. 
  • Maintenence of stability of these frequencies is called Hardy-Weinberg equilibubrium, the allele and genotype frequencies do not chabge over the course of many generations. 
  • An equilibrium is a null hypothesis, which suggets the evolutionary change is not occurring. 
  • When researchers investigated other genes in various populations, chi square value is obtained, hypothesis that the allele and genotype frequencies are in Hardy-Weinberg equilibrium is rejected. 
  • This means that the population is disequilibrium. 

Overview of microevolution 

  • Genetic variation is natural population typically changes…

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